Drug delivery devices in the form of infusers are known in the prior art for administering medicament to a patient. Infusers are intended for mounting onto a patient's skin for self-administration of a medicament. Activation of the infuser not only provides for injection of a needle into a patient's skin, but also to cause auto-drive of a plunger to drive medicament into the patient via the injected needle. Typical infuser constructions have the needle fixed to the reservoir. For example, with reference to U.S. Pat. No. 5,858,001 to Tsals et al., an infuser is disclosed that is activated through swivel displacement of a reservoir-containing body. A needle that is also caused to penetrate the skin of a patient with the swivel displacement of the body is attached to the Tsals et al. device. The needle is fixed to the body to move therewith. Other types of infusers are known, including those which use standard needle-mounted syringe barrels. With many infusers, the ability to control the insertion of the needle independent of the administration of medicament is limited.
PCT Publication WO 2011/146166, which is hereby incorporated by reference in its entirety, discloses an infuser in which activation of an actuator causes a spring to move a stopper in a reservoir from a first position toward a second position, and also causes a needle driver to displace a patient needle from a first state toward a second state. The needle moves relative to the reservoir, and separately from the stopper.